feat: adaptive bitrate support, engine improvements, demo updates, and electron preload

src/App.vue

@@ -111,6 +111,10 @@ watch([() => store.qteTimeRelax, () => store.qteSingleKey], () => {
   applyQteParams()
 })
 
+watch(() => store.preferredQuality, (q) => {
+  engine.videoManager.streamingQuality = q
+})
+
 watch(
   () => [
     showPauseMenu.value, showMenu.value,